Symbol Ba Atomic radius: pm 217 Fusion: kJ/Mole 7.12
Name Barium Ionic radius: pm (+2)142 Boiling point: C 1897
Atomic number 56 Electron affinity 0.15 Melting point: C 727
Atomic weight 137.3 1st  ion potential 5.21 Specific Heat Cap: J/(g K) 0.20
Classification Alk earth metal Natural form Solid Thermal Cond: W/(cm K) 0.18
Configuration [Xe]6s2 Crystal structure BCC Electrical Cond 0.03
Oxidation states 2 Density 3.62 Abundance: mg/kg-crust 425
Electronegativity 0.89 Vaporization: kJ/Mole 140.0    
Barium was discovered in other compounds in 1774 by Carl Wilhelm Scheele.  It was isolated by Sir Humphrey Davy in 1808. Uses - x-ray imaging agent, glassmaking, making rubber, rat poison